The present invention relates to a head capping device that includes a capping unit which can move to a first position, which is spaced apart from a recording head, and a second position, which comes into contact with the recording head to seal a nozzle orifice array composed of nozzle orifices, by an actuator.
The present invention relates to a liquid ejecting apparatus incorporating such a head capping device.
A liquid ejecting apparatus is not limited to recording apparatuses, such as an ink jet recording apparatus a copy machine, a facsimile or the like, in which ink is ejected onto a recording medium, such as recording paper, from a recording head serving as a liquid ejecting head, so that recording is performed on the recording medium. Examples of the liquid ejecting apparatus include various apparatuses in which, instead of the ink, liquid for a specific purpose is ejected onto a target medium from a liquid ejecting head, so that the ejected liquid adheres onto the target medium. In addition, examples of the liquid ejecting head include the above-mentioned recording head, a colored material ejecting head that is used for manufacturing a color filter in a liquid crystal display or the like, an electrode material (conductive paste) ejecting head that is used for forming an electrode in an organic EL display or a field emission display (FED), a bioorganic material ejecting head that is used for manufacturing a biochip, a sample ejecting head that serves as a micropipette and ejects the sample, or the like.
As an example of the ink jet recording apparatus or the liquid ejecting apparatus, there is an ink jet printer. The ink jet printer comprises a carriage that mounts an ink jet recording head, and the carriage is reciprocally driven in a primary scanning direction by a carriage motor while being guided by a guide member (for example, a guiding shaft) that extends in the primary scanning direction.
Here, if the recording head continuously performs the recording on the recording medium, clogging or the like may occur in a nozzle orifice from which the ink is ejected, so that superior recording cannot be performed.
Accordingly, in order to maintain a state of the nozzle orifice as a superior state, the recording head performs the so-called flushing operation in which it moves to a head capping device during recording so as to eject the ink toward a cap. Then, after the recording is completed, the recording head moves to the head capping device so that the nozzle orifice is sealed with the cap. Then, the so-called suction operation is performed in which a pressure of the cap is turned into a negative pressure by a pump, so that the nozzle orifice is sucked.
When the flushing operation or the suction operation is performed, in order to determine the relative positional relationship between the recording head and the cap, a claw that can come into contact with the recording head is provided in the cap. Japanese Patent Publication No. 2002-307701A discloses such a head capping device in which a cap holder is provided with a claw and moves integrally with a cap.
Here, since the claw and the cap move together, when the flushing operation is performed, the distance between the cap and the recording head is increased, which results in occurrence of the mist.
Accordingly, it is suggested a head capping device in which a claw comes into contact with one side face of the recording head in a primary scanning direction to decrease the distance between the cap and the recording head at the time of flushing operation, thereby preventing the mist from occurring.
As shown in FIG. 18, a recording head 401 formed with nozzle orifices is mounted on a carriage. A claw 403 that can come into contact with the recording head 401 is formed in a capping unit 402.
When the flushing operation and the suction operation are performed, the carriage moves at a high speed in a direction shown by an arrow, and reduces a moving speed near a position opposing the capping unit 402. The recording head 401, which moves at a low speed, comes slowly into contact with the claw 403 of the capping unit 402 at the position shown in FIG. 18, so that the shock due to the contact can be decreased. When the recording head comes into contact with the claw 403, the recording head 401 pushes down the claw 403 by the driving of the carriage motor, and the urging force with respect to the carriage side is applied to the capping unit 402 by a spring (not shown). Accordingly, since the recording head 401 and the claw 403 come into contact with each other without clearance, the relative positional relationship between the recording head 401 and the capping unit 402 are determined with high precision. Then, the driving of the carriage motor is stopped. In this state, the ink is ejected from the nozzle orifice, that is, the flushing operation is performed.
In addition, the waiting position of the capping unit 402 is set to the distance from the recording head 401 to the extent that the mist can be prevented from occurring, and the distance to the extent that the cap does not come into contact with the recording head 401 when the carriage moves. Therefore, when the flushing operation is performed, the cap does not need to move.
Here, when the suction operation is performed, after the driving of the carriage motor is stopped, the capping unit 402 moves to and then comes into contact with the recording head so as to seal the nozzle orifice. Then, the pressure of inside of the carriage is turned into the negative pressure by the pump, and the nozzle orifice is sucked.
However, in order to prevent that the recording head abuts against the claw, since the recording head reduces the moving speed near the position opposing the cap so as to move at a low speed, the throughput may be decreased.
Further, when the recording head comes into contact with the claw to be placed in a predetermined position, the load applied to the carriage motor includes not only the moving load for the carriage but also the urging force of the cap. Therefore, the load for the carriage motor is increased, which results in making it difficult to reduce the size of the carriage motor.
In addition, when the cap is released from the state which seals the nozzle orifice, the cap and the recording head may adhere to each other due to the pushing force or the ink. Incidentally, the load for the adhesion releasing force and the load for the frictional resistance force between the claw and the recording head are simultaneously applied to an actuator for moving the cap, which results into making it difficult to reduce the size of the actuator.